Amazon.com under investigation by the U.S. Postal Service

The U.S. Postal Service’s law enforcement arm has opened an investigation into Amazon.com Inc., though neither the federal agency nor the company will make the details public.

The third paragraph on page 67 of Amazon.com’s annual income filing says, “In January 2009, we learned that the United States Postal Service, including the Postal Service Office of Inspector General, is investigating our compliance with Postal Service rules, and we are cooperating.”

An Amazon.com spokeswoman declined to comment. An inspector with the Postal Service’s law enforcement arm declined further comment to The Associated Press.

Update: I have filed a Freedom of Information Act request with the Office of Inspector General of the US Postal Service. Thanks for your comment below!

Update: USPS’s Office of the Inspector General is a team of special agents that investigates “internal crimes and frauds against the Postal Service.”

The office completed 7,679 investigations last year, which resulted in 1,649 arrests or indictments and 769 convictions. Investigators recuperated $25.7 million in fines.

The U.S. Postal Service relies upon e-commerce retailers for business, as so many other forms of mail go electronic. This 2006 story from the New York Times describes the usually warm relationship between companies such as Amazon.com and eBay with the Postal Service.